Also in the field of wristwatches, a so-called radio-controlled watch configured to receive an external radio wave containing time information to adjust time that is held inside the watch has become widespread in recent years. In general, the radio wave received by the radio-controlled watch is along radio wave called “standard radio wave”. Such standard radio wave reception is subject to geographical restrictions, and is disadvantageous in that the reception takes time because a low-frequency carrier wave is used.
To cope with this, there is proposed a radio-controlled wristwatch configured to receive an ultra-high frequency wave used in a global positioning system as represented by the Global Positioning System (GPS). Radio wave reception from GPS satellites is free from geographical restrictions, and requires a short time owing to the use of an ultra-high frequency wave having a large information volume per unit time. As a typical example, Patent Literature 1 describes a GPS wristwatch configured to receive a satellite signal from a GPS satellite to adjust the time based on GPS time information contained in the satellite signal.